1. Technical Field
The present invention relates to a method and an apparatus for using the trajectory of an object to access video contents, for example, to specify and display a specific video image scene.
2. Prior Art
To access the contents of a video, which constitutes a sequential media, a time must be designated for the portion that is to be accessed. Relative to this, the advantage of digital video is that immediate access to a desired scene is possible so long as a time is designated. However, to access a desired portion, the use of a specific guide is required. Presently, according to a typical technique used for this purpose, a story board is used whereon shot change images are arranged, and a desired shot change image can be accessed by clicking on the image. But there are video contents for which shot changes are meaningless, and only an image acquired at a specific time in a scene between shots can be used as a representative image. For example, in spots, shot changes are repeated for unimportant scenes to prevent a user from becoming bored, while for an important scene, images acquired using a camera with which it is anticipated the best images can be obtained are continued so as not to miss a moment of the important scene. Therefore, since an important scene may be missed by using a representative image obtained as a shot change, an interface is required with which a scene can be designated an important scene.
According to an example method for accessing the above video contents, the trajectory of an object is extracted from the video, and is used for a video search. With this method, however, the trajectory of the object is displayed and is superimposed on a video image on a display device, so that the display image is difficult to see and the video contents can not be efficiently accessed. Further, according to this example, the video search is performed only by matching trajectories. In addition, even if the video contents can be accessed the access efficiency is not satisfactory.
To resolve the above objectives, it is one object of the present invention to provide a video contents access method, for which the trajectory of an object is used, whereby the trajectory of an object that is displayed separately from a video image is used to efficiently specify and display a video image scene desired by a user, and also to provide an apparatus therefor.
The present invention relates to a method for using the trajectory of an object to access video contents to, for example, specify and display a specific video image scene. Such a video contents access method comprises the steps of: extracting objects from video contents; displaying the movements of the objects as trajectories on a specific projection screen; specifying locations along the trajectories; and accessing a desired scene contained in the video contents.
Furthermore, according to the present invention, a video contents access apparatus comprises: display means for displaying, as trajectories on a specific projection screen, the movements of objects extracted from video contents; and instruction means for specifying locations along the trajectories, whereby the above described video contents access method is performed.
According to the present invention, the objects, such as the states of players, are specified by using trajectories displayed on a projection screen, without directly providing a video for a user. Therefore, the process performed by a computer is simplified, and it is anticipated that the status of a game will be reported to a user, even if the trajectories of the objects are displayed at high speed. In addition, the user can use a trajectory to determine which video frame is to be accessed, and only when the user selected a point on the trajectory can the current frame jump to a corresponding frame and can a video be replayed. Furthermore, since the information carried by a trajectory interacts with an actual object in the contents, such as an individual player or a ball, to the user it will seem as though he or she is controlling it directly. As a result, the desired video image scene can be efficiently specified and displayed.
As the preferred embodiment of the present invention, the trajectories of the objects are those that are displayed, in order with time for video contents, in a time interval lying between a currently displayed video frame and a preceding video frame that was displayed a predetermined time period earlier. Furthermore, a user can control the speed at which the trajectories of the objects are displayed. A scale (play advantage) for representing an important scene is displayed on a projection screen by using the trajectories (Traj) of the objects, which are calculated using the following equation: Traj=(object ID, start time, end time, line graph representation). The video data are digital video data, or analog video data that can manage time code. Furthermore, a window for displaying images of said video contents and a window for displaying said trajectories of said objects are displayed on the same projection screen. To specify said locations on said trajectories, points on the trajectories are designated by using a pointing device. In this embodiment, a plurality of video objects are used, and with this arrangement, the present invention can be efficiently carried out.